1. Field of the Invention
The present invention is an improved system and method for making a frame alteration in a network processing environment. More particularly, the present invention employs fixed hardware alterations as well as flexible software alterations in the environment of a processing system coupled to a network to alter frames at the speed of transmission (media speed).
2. Background Art
Networks are carrying more and more communications, especially with the increase in importance of the Internet and intranets. Some of this information is in the form of digital data, other is in the form of voice information which has been converted into information packets. Whether the information is data or voice, however, it is formed into packets or frames of an appropriate size, then addressed to the destination and sent over a network which includes a plurality of switches or routers to get from the source to the destination. As the amount of information flowing over networks increases, so does the need for equipment to efficiently handle such information as ever increasing speeds and with greater efficiency.
Such frames typically includes the information (voice or data) along with appropriate routing and protocol information, encapsulated into one or more headers to provide the necessary information to direct the frame to the correct receiving location (the destination address) in the proper format and allow it to be received and decoded at the receiving location. Along the way, it may be necessary for the frame may change formats and encapsulated headers may be added to or deleted from the frame through the use of frame alterations.
Various systems are known for processing frames in a network environment. Some of the known systems merely transmit the frames as received to a processor which then adapts the frames to the protocol for the receiving apparatus. Some involve using hardware to remove or change parts of the frame and others involve software or programming to make changes to the frame. While changes to a frame through the use of hardware generally can occur more quickly because they involve only a few gates and minimal delays, such hardware alterations to a frame generally lack flexibility to make a variable change. On the other hand, using a programmed set of instructions to make changes to a frame allows an alteration to be made in a variable manner but usually at a significantly slower speed, since changes using a programmed set of instructions may involve executing of many instructions with conditions and branches, which consume many cycles of the clock and occur in an amount of time which varies according to the number of instructions which are actually executed. Accordingly, software alterations typically operate slowly (not at the speed that the transmission of frames requires), a slowness that would otherwise slow down the entire system.
In a network environment, a variety of frames are passing through a router or switch, with varying origins, destinations and formats. As the speed at which such switches and routers operate increases, it is desirable that the router or switch operate at real time and yet have the capability of providing an alteration to frames which is variable (allowing for change in requirements) while operating quickly.
These systems have limitations and disadvantages that programming a switch or router to remove or alter the frame would require a large amount of programing, requiring either a very high speed processor or a delayed time to respond.
Accordingly, the prior art systems have undesirable disadvantages and limitations in their speed and flexibility—they are either slow and flexible requiring a variable amount of time or fast and inflexible—when a system is needed for making frame alterations that is both fast and flexible.